The chaotic state of understanding of the mechanisms involved in the pathogenesis of phakoanaphylactic endophthalmitis has resulted from piecemeal studies attempting to demonstrate that autoimmunity to lens proteins may participate in the inflammatory process. The relative roles of specific immunopathologic mechanisms have not been adequately evaluated. We propose to investigate the pathogenesis of lens-induced uveitis in a systematic and coordinated fashion, comparing and relating histopathologic and electron microscopic observations to immunologic indices within a organized setting of clinical and experimental situations designed to isolate the specific contributions of the various immunopathologic mechanisms in uveitis.